The present invention is directed to a method and computer apparatus for efficiently damping vibrations in an electric machine. More particularly, the invention is directed to efficiently damping vibrations in an electric machine having a three-phase power supply.
Control methods for electric machines are known in various embodiments. A so-called regulated operation is in particular known for instance for electric synchronous machines. During regulated operation, the first active part is applied with a quadrature-axis component of current, which is precisely sufficient to cause a movement of the second active part of the electric machine relative to the first active part on account of the quadrature-axis component of current. Regulated operation is required for instance for linear drives in DE 101 50 318 A1 and DE 101 50 319 C1. Regulated operation is also required in DE 10 2008 008 602 A1.
A so-called controlled operation is further known for synchronous machines. During controlled operation, the first active part is applied with a direct-axis component of current, which is sufficiently large to safely cause the movement of the second active part of the electric machine relative to the first active part. The quadrature-axis component of current is kept as low as possible or is controlled by specifying a corresponding target quadrature-axis component of current value. By advancing the direct-axis component of current according to the desired movement, the relative movement of the second active part relative to the first active part follows the magnetic field produced by the direct-axis component of current. During controlled operation, also often referred to as I/f operation in practice, mechanical vibrations may however result, which are overlying the desired relative movement of the second active part relative to the first active part. In many instances, a damping of such Reference is made purely by example to DE 195 19 238 A1.
However, the methods and apparatus that are known in the art do not reliably provide vibration damping over the entire speed range of the apparatus. A means and method that efficiently damps vibration generated during relative movement of components over their entire speed range is readily provided in accordance with the invention.